Low level scanner and analog to digital converter



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LOW LEVEL SCANNER AND ANALOG y0 DIGITAL CONVERTER Filed lay 6, 1957 6 Sheets-Sheet 5 E. A. KELLER Oct. 11, 1960 LOW LEVEL SCANNER AND ANALOG TO DIGITAL CONVERTER Filed May 6, 1957 6 Sheets-Sheet 6 portant where a large United States Patent O LOW LEVEL SCANNER AND ANALOG T DIGITAL CGNVERTER Ernest A. Keller, Wilmette, lll., assignor, by mesne nssignments, to Information Systems, Inc., Skokie, lll., a corporation of Illinois l l Fired May 6, 1951, ser. N6. 651,265

13 Claims. (ci. 340-341) This invention relates to data information systems, and particularly, althoughnot necessarily, to a system which receives analog voltage signals from low level transducers, such as thermocouples, associated with variables to be monitored and then converts the analog signals to coded, preferably binary coded, signals which are stored for further handling. I

the analog signals to binary coded signals which are i Astored or immediately fed to suitable recording apparatus, such as electric typewriters, where the actual values of the variables are printed out on a record'sheet. The measuring devices usually included either a motor driven self-balancing potentiometer system with a mechanical shaft-driven analog to digital converter, or a primarily electrical measuring or electronic circuit which per-v digital conversion electrically from f The output of the analog to digiformed an analog to the transducer signals. tal converter was sometimes already in binary coded form and in other instances had to be converted to a binary coded form by `suitable coding networks. 'Ihe resultant binary signal was then stored in suitable storage means forming a completely separate and distinct part of the system.

The above-mentioned prior systems left a great many things to be desired. For example, since a common measuring device was sequentially connected to the outputs of the transducers, the problem of impedance mismatch of the transducer circuits was present where the transducers were not all alike. Also, where the transducers are low-level signals such as is commonly found in thermocouples, the signals in passing through mechanical scanning switches picked up spurious noise signals caused by arcing, switching transients and the like which i atected the degree of accuracy and speed attainable.

Also, the reliability and service life of the equipment was limited due to the wearing of contact surfaces, and the problems of servicing the equipment. The question of size and weight becomes exceedingly critical where the equipment is to be carried in aircraft or where strict floor space limitations exist in the factory or plant where the equipment is to be located.

The present invention has many aspects, some of which overcome only some of the above-mentioned disadvantages and others of which overcome many and sometimes all of the above-mentioned disadvantages. Among the objects of the present invention, therefore, are: to provide a data handling system wherein particularly low level signals may be handled, converted to binary coded form and stored without the need for mechanical or elecponents thereof, and the tronic switching of analog signals; where substantially.

increased accuracy and reliability are obtained because the measuring part of the system does not have or is not sensitive to the switching noises found in the mechanical and electronic scanning systems heretofore utilized; to

provide such a. system which can operate at greatly in creased scanning rates because the speed of operation is to pronot limited by decay rates of switching transients; vide such a system which is substantially lighter in weight and occupies only a small fraction of the space required by such prior equipment; to provide such a system which can be used in explosive sparking is avoided; to provide such a system wherein the components are rugged, simple and reliable in operation so the equipment can last almost indefinitely and will operate substantially without failure; and to provide a system which, for a given cost, is faster operating, more accurate and reliable than prior systems.

In accordance with one aspect of the invention, the analog voltage outputs of the primary measuring devices or transducers, instead of being passed through a scanning'switch, are ,fed to the inputs of separate comparator circuits. The comparator circuits form an element in an analog to'digital converter where the-outputs of the transducer are, in a sense tp be explained, scanned without varying the D.C. load impedance of the transduee circuits, as would be the case where the transducer out puts are fed through switch contacts or electronic gate circuits. The scanning means includes a source of a.- progressively varying amplitude signal which is fed to each comparator circuit. Most preferably, the reference equipment required special airftight housings when used in explosive atmospheres due to contact sparking. With electronic switching systems, noise pick-up was also a a problem, although to a lesser degree, as was the fact that the electronic switching systems could not operate directly with the low level signals but required initial amplification Vwith separate D.C. amplifiers for couple output which added to the the system.

Limitations on scanning speed become exceedingly imnumber of variables ane to be constant monitoring of all yvaricost and complexity of monitored and almost ables is desirable. y

.Other important disadvantages of the above-mentioned prior systems are in the great over-all size and weight of the equipment, the expense andcomplexity of the comeach thermoin the temperature variable.

signal amplitude varies in very small discrete steps, the sizes of the steps being determined by the range of accuracy desired and the comparator characteristics. For example, the reference signal may have a stepped waveform wherein each step represents a variation in the ther- 4 mocouple output corresponding to one unit change in the associated variables or wherein each such the same elect in the comparator circuit as a unit change The comparator circuits are each adapted to generate a control pulse or signal anytime there is correspondence between the reference signal and the transducer output fed thereto. The output pulses of the comparator circuits thereby appear in time sequence unrelated to thel position of connection of the transducer outputs but rather correlated values of the transducer signals associated coding means provides a progressively code synchronized with the change of reference signal source. erates an output pulse, a signal is stored in a corresponding storage position of a suitable storage unit which is correlated to and indicates the coded signal produced by the coding means at the instant the pulse in question was generated.l A similar signal is simultaneously stored in therewith.. A varying binary the steps in the a corresponding storage position for all transducers proatmospheres because contact s tep produces to the analog As a comparator circuit gen- 3 magneticcorehavingarectangularhysteresiscurvetwo input windings for respectively receiving the transducer signal and the output of said reference signal source and an output winding in which a pulse is generated by the core whenever the magnetomotive forces produced by the two inputs are substantially equal and opposite in direction. Normally, the core is in a reference state of saturation which is maintained by the current in the input winding connected to the associated transducer. The current signal in the input winding connected to the reference signal source progressively increases in a'drrection which opposes the etfect of the transducer current in the other input winding. When the results-"of these two currents are the same, the next level of `the reference signal drives the core to the opposite state of saturation, thereby inducing a control pulse of appreciable magnitude in the output winding. v Preferably, the of the various steps of the reference signal source is synchronized directly or indirectly from a source of timing pulses. lThe source of pulses either control or are controlled by the coding means. Preferably, the coding meam comprises a pulse counter, a scale-of-two counter, which has a number of output lines corresponding to the number of binary code bits in a code group, the binary decimal coded groups in elect identifying the particular level of the output of the reference voltage source. However, in the broader aspect of the invention, other types of coding means could be provided. The various stages of the scale-of-two counter are bistable units which control the current or voltage generated by the reference signal source. Bach stage controls preferably the conduction of one of a number of current paths having individual load resistors and connected in parallel with each other and in series with a relatively low load resistance connected in common to all of the current paths. If the combined parallel resistances of said current 'paths is substantially larger than said common load resistance and the resistance therein are related by a power of two in inverse relationship to the order of the associated scale-oftwo pulse counter stage, then the current iiow through said common load resistor will increase in identical discrete steps if conduction and non-conduction of the current patls correspond with the instantaneous bistable state of the associated stages.

The above-mentioned storage unit is arranged so that it can theoretically receive information from the signal sources in all storage positions thereof substantially simultaneously since the instants of entry of information therein within a scanning cycle -is solely a function of the values of the associated variables. In the most preferred .form of the invention, the storage unit includes a magnetic core matrix which may itself be of more or less conventional construction but which is utilized in a 'novel manner to accomplish the results desired by the invention. Conventional magnetic core matrices have a number of rows of magnetic cores. In the present invention, the cores in each row represent different bits of a multi-bit binary code group which is to represent the value of the associated variable and each auch row corre sponda to one of said storage positions. The cores are preferably of the type having a rectangular hysteresis curve, a saturated state of magnetization beyond onegosen-1r isinsetieswththeontputwindingofeachoftheother cores.

In accordance with the invention, the outputs of the various comparator circuits, which in the preferred form of the invention are output windings of magnetic core units, are each connected to the tirst input windings of the cores in the corresponding or associated row of cores. In the case where the coding means is a pulse counter, each of the output binary code bit lines of the counter are connected to the second input windings of the corresponding column of the core matrix. The windings of the cores are designed so that the cores will be driven from a given reference state of magnetization to the opposite state of magnetization when the input windings thereof both have signals of a given polarity occurring simultaneously. With the particular connection of the magnetic core matrix to the coding means and the amplitude comparator circuits above outlined, the magnetic cores of the respective rows of the matrix will have magnetic states corresponding to the binary codes which" I represent the values of the associated variables, the scquence of the signal entries in these rows being determined solely by the values and not the order of connection of the variables to their transducers.

Following the completion of an amplitude scanning cycle of the reference voltage source, the coded signals storedinthemagneticcorematrixcanbereadoutaequentially to other suitable storage means, such as a magnetic drum, or directly to an output recording device such as an electric typewriter. The code groups may be read out by pulsing sequentially the row and column in put lines of the matrix with a signal which will drive the cores set to said opposite state `of magnetization back to said reference state of magnetization. The change of magnetic state in any core will induce an output pulse in the output winding ofthe core.

In order to decrease the scanning period so that it 'is not necessary to await the sequential readout of the 'information stored in the code storage means before beginning a new scanning cycle, a pair of said code storage units are provided so that while information on certain variables is being read out from one ofthe storage units, fresh binary coded information on the same or other variables is taking place in the other storage unit. Since storage and readout operations are occurring simultaneously, scanning is continuous.

It can thus be seen that the above-mentioned form of the invention alleviates the various disadvantages above described. In the first place, the therrnocouple outputs are not switched in the normal sense through mechanical or electronic switches and the invention avoids the unl desirable contact sparking, noise pickup and mismatching of the transducer load impedances. Moreover, the scanning rate is not limited by switching transients and the like, permitting n much higher scanning rate than was heretofore possible. Greater accuracy, speed and reliability thus result from the arrangement of the present invention. In the second place, the number of components is drastically reduced, particularly in the preferred form of theinventio'n above described. The magnetic cores constituting the comparison portion of the anolog to digital converter performs both comparison and amplifying functions, the amplifying function being the generation of a current or voltage pulse indicating the presence of a given state of comparison between the reference volt. age and the transducer output. Amplitude comparisonA circuits of a type heretofore utilized (for completely different purposes than in the present invention) have operated on a principle which resulted in a generation of a signal which was a function of the magnitude and direction of the dierence between the two signals being A acusan unit forming the comparison circuit. Moreover, in the i preferred form of the invention, the magnetic core storage means both aids in the conversion operation and acts as a buier storage Ifor the coded signals.' The use of magnetic cores for scanning conversion and storage in the manner above explained greatly the size and weight of the equipment and increases the reliability Alternatively, the scale factor correction can be made within the comparator circuit itself. When the level of the stepped waveform-6' and the transducer derived signal compared therewith in a given comparator and longevity of the equipment relative to the kind of equipment heretofore used in variable measuring and recording equipment.

Other objects, advantages and features of the invention will become apparent upon making reference to the specification to follow, the claims and the drawings wherein: i 4

Fig. l is a basic box diagram showing the over-all arrangement of components in the present invention;

circuit reaches a given state of comparison, an output pulse is generated at the output of the comparator circuit. At any given instant of comparison, pulses are generated .in each and every comparator circuit output whose transducer derived signal input represents the same numerical variable value. The binary code signal at the output of the coding means 8 changes at the beginning of each level of the stepped waveform 6' to indicate a new number,

preferably only one unit greater than or less than the previous number, representing the value of the variable which the system is looking or scanning forat the various transducer outputs at that instant.

Figs. 2a and 2b together show the most preferred form comparator circuit y Figs. 6a and 6b show a relay storage matrix which, in

the broader aspects of the invention, may be utilized instead of the magnetic core matrix shown in Figs. 2a and 2b; and A Fig. 7 shows a still further modification of the invent tion utilizing a 'magnetic drum in place of the magnetic core or relay storage matrix of the more preferred forms ofthe invention.

Referring now to Fig. l, the basic system of the invention includes a large number of signal sources 2 in the form of transducers which provide analog voltage outputs which are a'measure of the values of the variables to be monitored and measured by the system of the invention. When the transducers are thermocouples, the level or magnitudes of the outputs thereof are exceedingly small which creates problems of the kind outlined above in the introductory portion of the specilication aecting the speed and accuracy of the system. In accordance with the present invention, the output of the transducers 2 are connected respectively to one of the inputs of separate comparator circuits, 4a, 4b, 4c, etc. Each of these comparator circuits has a second input fed in common by an input signal control means 5. The input signal control means provides an analog control voltage or current,A

signal in the form of a signal having a progressively varying amplitude, most preferably a stepped waveform 6',

and a progressively varying multi-bit binary signal representing the level of the analog signal `at any instant. These two signals should be accurately synchronized and can be generated by completely separate .but synchronized circuits or may be derived from the same circuit or different parts of the same circuit, in a manner to be explained. For example, the binary coding means may form part of a step wave generator circuit by directly controlling the level of current or voltage in the analog outl," put portion of ther circuit. In any event, those circuit L components forming the analog output will be sometimes referred to as step wave generator means 6 and the components which form the binary output will be sometimes referred to as coding means 8, even though common components may be involved. Where the analog control signal has a stepped waveform, each step is equivalent to a change in one apparent unit of the value of the variables involved. In the case where the transducers have different scale factors, the outputs of the transducers duce the same change at the input of the comparator cir- The coding means 8 is associated with a code storage means 10 having separate inputs 10a, 10b, 10c, etc. t0 which the various outputs of the amplitude comparator circuits 4a, 4b, 4c, etc. are respectively fed. The code storage means performs an important function in the analog to digital conversion operation to be performed,"y

and includes a separate storage position for each variable in which is to be stored an indication of the multi-bit, 1 binary coded number which represents the value of the variable involved. The code storage means includes means responsive to the signals on the output lines 10a, 10b, 10c, etc. of the comparator circuits and to the code indication of the coding means at the instant of generation of the signals at the outputs of the comparator circuits for storing in said storage positions the coded indications of the values of the variables involved. The information in the various storage positions of the'code storage means 10 may be read out when desired sequentially in the order of the storage positions to operate other data handling devices, usually operated by the feeding of successive data signals thereto, by suitable sequential f switching means 13. The system just described does not l' require the switching of the analog voltage outputs of the transducers 2, and thus, to a great degree, avoids the accuracy and speed 4limitations inherent in the mechanical and to a lesser degree the electronic switching of low level analog signals as in prior scanning systems. The mechanical or electronic switching of 'binary coded information does not, of course, suer from the disadvantages inherent in the switching of analog voltage signals.

In the broadest aspect of .the invention, the various components above described may take a variety of forms. More specific aspects of the invention, however, deal with specific types of components and their novel relationship with various other parts of the system.

Refer now to the embodiment of the invention illustrated in Figs. 2a and 2b, which is the most preferred form of the invention. In this embodiment, both the comparator circuits 4a, 4b, etc. and the code storage means 10 are made of magnetic core units preferably of code storage units 10 and 10 are provided so that while information on certain variables is being sequentially read out from one of the storage units lll or 10', fresh binary coded information onthe same or other variables is being taken in the "other storage unit.v Since storage and readout operations are occurring simultaneously, for-a given number of variables, the time between successive scannings of any variable is reduced by a factor of one half.

In other words, the system substantially continuously scans the variables involved and continuously stores and reads out data on the variables.

Each of the magnetic core units 4a, 4b, etc. comprises a ring 4a-1, 4b-1, etc. of permanently magnetizable matcrial having the rectangular hysteresis curve in Fig. 3. 'nre ge of one of the tubes of each stage alternates between a high positive potential and a low potential as it is respectively triggered between non-conductive and conductive states. Output lines 8a, 8b, 8c, etc., extend from the plates of the normally non-conducting tubes of the respective stages of the counter and, in the normal condition thereof, they have a high positive voltage thereon which is higher than the output source El applied to the diodes 6a-1', 6b-1', etc. The counter output lines 8a,

v8b, 8c, etc., contain the binary code signals fed to the storage units 10 or 10' and, accordingly, may be connected thereto through and and not gates Btl-2a and Sil-2b' (Fig. 2a). The output lines 8a, 8b, 8c, etc., are also connected respectively to the anodes of diodes 6ta-l, 6b-1, 6c-1, whose cathodes are respectively connected to the cathodes of the diodes 6a-1', 6b-1' and 6c-l' so that the current normally owing through the former diodes renders the latter non-conductive. As the counter tube to which each of the output lines 8a, 8b, 8c, etc., is connected is rendered conductive, the associated diode 6a-1, 6b-1 or 6c-1, etc., becomes non-conducting and the associated current path and diode 6a-1', 6b-1' or 6c-1 becomes conducting. The current flowing connected t all of the"'and" gates numbered i-a' ami theotherline-2bisconnectedtoa1lofthenotgates numbered Btl-2b'. 'A high voltage fed to the input of any of these gate circuits will open the gate Iand a low voltage fed thereto will close the. gate. Obviously the gates 30-2a' and 30-2b' are opened during the alternate cycles of operation of the step wave generator. These various gate circuits control the switching of the various inputs and outputs of the storage units 1t! and 10 and other switching operations to he described.

Referring again now more particularly to Figs. 2a and 2b, among other things it has`been-explained how the coding means 8 provide a binary coded output on its output lines identifying each level of the output of the step wave generator 6 and how the output pulses in the comparator circuits are produced. These various outputs are alternately connected to the storage units 10 and 10 which will now be described. In the most preferred form of the invention, each of the storage units comprises what is generally referred to as a magnetic core matrix. In a magnetic core matrix, magnetic cores such as 10a-1,

- 10a-2, etc.; '10b-1, 10b-2, etc. each in the shape of a through the core windings 4a-3, 4b-3, etc., is the sum of the currents owing through the current paths conducting at any instant and, due to the relationship' of the values of the path resistances 6a-I, 6b-1, and 6c-1 and the binary code provided by a scale-oftwo counter, this current tlow is proportional to the number of pulses fed to the counter since the beginning of the count cycle involved. The cores could be replaced by a suitable current amplifying means, such as a transistor amplier which drives the core windings.

As is conventional in binary counters 23, a sharp pulse may be generated as the output tube in each stage changes conducting states by means of a capacitorresistance differentiating circuit such as 8a-4, 8b-4, or 8c-4, etc., connected to the plate of such tube. The polarity of the pulse depends on the direction of change of the state of conduction of the tube involved, and only pulses of a given polarity are fed to the succding stage of the counter by means of diode rectiers 8a-3, 8b-3 or 8c-3, etc. connected to the low voltage side of the associated capacitor. It can be seen that with a counter arrangement of this type, the highand low voltage conditions of .the output lines 8a, 8b, 8c, etc. at any instant will represent the binary code identifying the particular level of the reference signal waveform at such instant. The pulse counter 8 may be a self-resetting counter circuit so that after a given number' of pulses, the counter will reset itself to zero or any other reference number. This will also reset the step wave generator so that it can begin a new cycle of operation.

The outputofthepulse source 16 is alsofedto aprogrammer (generally indicated in Pig. 2a by reference numeral 30). The programmer may comprise any suitable pulse counter 30-1 to which the pulses from the pulse source 16 are fed. When the pulse counter 30-1 has received a number of pulses equal to the number of steps desired in the step wave output of the step wave generator 6, a pulse is produced in its' output which is fed to a suitable bistable circuit 30-2 which, like each stage ring, are arranged in successive horizontal rows with the corresponding cores of each row falling in respective columns. Bach of the cores has the rectangular-type of hysteresis curve shown in Fig. 3 and the cores of each row of cores have a wire 10a, 10b, 10c, or 10d, etc. passing through the various cores so as to constitute serially connected input windings for the various cores in each row. Similarly, wires 11a, 11b, 11e, 114, 11e, 11f, 11g, 11h, 11i. or 11i, etc. pass through the centers of the cores in the respective columns of cores to form serially connected input windings for the cores in each column. A single wire 12 extends through all of the cores of each storage unit to constitute serially connected output windings. Prom this arrangement of the magnetic core matrix, it is apparent that a current pulse flowing through any of the horizontal or row wires 10a, 10b, 10c, 10d, etc. will momentarily produce a magnetomotive force in each of the cores of that row. Similarly, a current flowing in any netomotive force in all of the cores of the column in volved. The design of each core unit is such that upon the simultaneous occurrence of current ow of a given polarity and exceeding certain predetermined values in the two input windings thereof that the core will be driven from a reference saturated state, which might be represented by curve segment S1 in Fig. 3. to the opposite state of saturation represented by the curve segment S3 in Fig. 3. If only one of the input windings contains a current of said proper polarity and magnitude, the core will not be driven between said above-mentioned states of saturation but will remain in its then state of saturation.

The various output lines, 8a, 8b, 8c, etc. of the coding means are alternately connected to the column lines 11a, 11b, 11e, etc. of the storage units 10 and l0' through and gates 30-2a' and not gates 30-2b', respectively, controlled by programmer 30 previously described, said respective gates being' open during alternate cycles of operation of the step wave generator 6 so that the storage units are alternately rendered operative for data read-in operations. In the same way, the outputs of comparator of the scale-of-two counter making up the coding means,

may comprise a two-position .stability multivibrator wherein each pulse in the output of the pulse counter reverses the conducting states of the two tubes thereof, only one of which is conducting at any instant. An output line 30-2a extends from one of the stages and an output line 30-2b extends from the other of these stages. When the tube to which each of these output lines is connected is conducting, the D.C. voltage on that line is at a relatively low positive potential or a negative potential, and when the associated stage is non-conducting, the volt- 'age on the associated output line is at a relatively high circuits 4a, 4b, etc. and 4a', 4b', etc. are connected to the row lines 10a, 10b, etc. of the storage units 10 and 10 through and gates 30-2a and not gates 30h', respectively during alternate cycles of operation of the step wave generator so that both the comparator circuits and the coding means are connected to the row and column input lines only when the associated storage unit is to receive information therefrom.

As above explained, one of the binary indications on each of the output lines 8u, 8b, 8c, etc. of the coding means is represented by a high positive voltage whereas: the opposite binary indication is indicated by a lower positive voltage. One of these output lines 30-24 is 76 positiveor anegative voltage. Ifdesired, however-,these 11 binary indications may be indicated respectively the presence or absence of a pulse. In the present example, the core of any magnetic core unit is not switched from a reference state of magnetic saturation to the opposite state of magnetic saturation unless the column line of a` particular core is receiving the high voltage-signal from the coding means at the same time that it is receiving a pulse of a given polarity from the output of the associated 'comparator` circuit. With this arrangement, it can be readily seen that 4the multi-bit binary code ndic'ated by the magnetic states of the cores in any particularrow will be a measure of the value of the associated variable. Thus far it is apparent how the storage unit or ables insuccessive cycles. It will now be explained how the information stored in any particular storage unit during a given scanning cycle is readout during tthe succeeding scanning cycle.

In data handling systems utilizing binary coded signals, it is quite common to feed each binary code group to a data handling device by the sequential feeding of the bits of each code group to such device, which might be are prepared to be returned to the reference state of magnetization, if they were previously in said opposite state of magnetization, when a pulse of proper polarity is fed to the associated column input line. Since the column shift register 13-2 need not provide its voltage forany length of time, the pulses sequentially generated 10 will receive information on different groups of vari-` on its output lines may directly drive the cores of the rows selected by the row shift register.

Whatever type of shift register or scanning switch is utilized, they would each have a series of output lines 13-111, 13-1b, 13-1c, 13-1d, etc. connected through not gates -2b controlled by the programmer 3U to the respective row lines 10a, 10b, 10c, 10d, etc. of the storage unit 10 and through and gates 30-2a', respectiveanother storage unit, such as the drum storage unit indicated in box form in Fig. 2a, or some other buffer storage device as indicated by reference numeral 36. To this end, suitable row and column switching units 13-1 and 13 -2 are provided which sequentially feed readout pulses to the various row and column lines 10a, 10b, 10c, etc. and 11a, 11b, llc, etc. in column by column and row by row succession 4in a manner which returns the magnetic cores which were previously driven to a second'state of magnetic saturation back to the reference state of saturation to thereby produce a change of .flux in the core as the unsaturated part of the hysteresis curve is reached. 1n effect, the condition of the cores in each row are scanned core by core and whenever the core scanned is in said second state of magnetization, a pulse is generated in the. common output line 12 or 'l2'. The switching units may take a variety of forms.

For example, they may be conventional telephone-type stepping switches which operate to feed sequentially the proper readout voltage to one of the storage units 10 or 10' on their output lines lz-la, l3-1b, 13-1c, etc., 13-2a, 13-2b, 13-2c, etc. while the other storage unit is receiving information from the comparator circuits and coding means. Following the completion of the readout operation on the storage unit involved and a read-in operation on the other storage unit, the switching units feed the read-out pulses to the latter unit.

The switching units 13-1 and 13-2 mayalso be magnetic core shift registers synchronized directly or indirectly from the timing pulse source 16. VA magnetic core shift register generallyconsists of a number of cascaded stages of magnetic core units which are initially in a reference state of magnetic saturation except for the lrst stage which is in the opposite state of saturation. So called advance pulses arevfed to the input of vthe shift register which pulses have a polarity which will drive any core in said opposite state of magnetization back to the reference state of magnetization. As a core is triggered back to 'the reference state of magnetization, it generates a pulse which appears on the output line thereof, such as 13-1a, or 13-lb, etc. of such stage and which triggers the followingv stage into said opposite state of magnetization. AsA each succeeding advance pulse is received, the cores successively assume said opposite state of magnetization, and the core which generated the pulse which triggered the core in such opposite state is at the same time returned to the reference state .resulting in a read-out pulse being generated at its output line 13411 or l3lb, etc. A magnetic core shift register is disclosed in the Automatic Control Magazine, April 1956 edion, pages 15 through 19.

In the case of row shift register 13-1, the pulses gen- 'Nowthatthelmst ly to the row input lines 10a, 10b, 10c, 10d, etc. of the storage unit 10'. The pulse appearing at the last output line, 13-2n of the column step switch or shift register would be used to advance the row switch or register one position to prepare the next row of cores for a read-out operation. The column step switch or register receives its advance pulses directly from the pulse source 16 via line 38. The binary code group stored in a particular row is thus readout in terms of the number and placement of pulses in a given time interval wherein at any reference time position within such interval one binary indication is represented by the presence of a pulse and the opposite binary indication is represented by the absence of s pulse. t

It will be assumed for purposes of a simplified representation of the invention, that the storage unit being readout will be completely scanned in the same time period required for one period of operation of the step wave generator 6. If this is not the case, then suitable interlock means must be provided for preventing the beginning of a new cycle of operation of the step wave generator 6 before the scanning of the storage unit then `being readout has been completed, or vice versa, de-

-andtheoutputlinelz'ofthestorageunitlo'isconnected (Fig. 2b) to the point 42 through an and gate 30.2a'. Inthismannertheoutputlineofthestorags umtwhichisbeingreadoutisconnectedtothepoint which leads storage device 36 through suitable gate circuits 44 and suitable ammmg' means (not shown). progr storedinthestotage devices 35 or36isreadoutto'l. suitable recording device 48 via rpeaive gates 50 and 52 also controlled by said suitable pro means.

preferred form of the invention, other and less preferred forms thereof will be described sothatthescopeofthebroadaspedsoftheinvention canbest be appreciated. Refer now to Fig. 5 which shows a less preferred form of comparator circuit which tolerated. In this embodim the thermocoupl transducers 2a, 2b. 2c, etc. arxconnected respectiveely z; D.C. ampliliers 54a, 54b, 54e, ete. 'Ihe outputs of the D.C. amplifiers are connected respectively through resistors 56a, 56b, 56e, etc. to the anodes 58a, 581:, 58e of diode rectifier tubes 59a, 591:, 59e, etc. whose cathodes 60a, 60b, 60e, eteueconneeted toground throughrespecnve resistors 62a, 62b, 62e, etc. The cathodes 60a, 60b, 60e, etc. are respectively connected to the cathodes 62a, 621, 62e, etc. of diode units 64a, 64b, 64e, etc.

tothedrumstel-ageunitsorothersuitable4 When desired, the' Informa' tion 'whose anodes 66a, 66h, 66e, etc. are connected through respective resistors 68a, 68h, 68e, etc. to the output of the step wave generator 6.

Assuming that the polarity of the outputs of the D.C. amplifiers is such that the output lines thereof have positive direct current voltages, the output of the step wave generator 6 is either directly or indirectly through suitable conversion means arranged to provide a stepped voltage waveform 6" which progressively decreases in etc. exceeds the output of the D.C. amplier's 54a, 54b, 54e, etc., the diodes 59a, 59b, 59e, etc. will be rendered non-conductive. As soon as the stepped voltage waveform 6" reaches a level which is below the output of the D.C. amplifier' involved, then the particular diode 59a, 59b or 59e, etc. involved will become conductive. voltage pulse thereby appears at the anode of the diode 14 ground branch line 90a leading to a main ground line 92. All of the other windings of the relay .units of any particular row of relay units corresponding to the first-mentioned winding 82a-1 are similarly connected between the associated row input lines 10a, 10b, 10c, 10d, etc., and the associated branch ground line 90a, 90b, 90e, etc.

The winding BZa-Z is connected between the associated column input line, which, in the example is column line 11a, and the associated branch ground line 90a. Likewise, all of the windings ofthe relay units in each column corresponding to the relay winding 8%-2 are similarly connected between the associated column input line 11a, 1lb, llc, etc., and the associated branch ground lines 90a, 90b, 90e, etc. y

One ofthe terminals of the third winding SIe-3 is connected to the holding contacts 82a-4, which are normally open, which contacts in turn are connected to a high voltf age branch line 94a extending to a main high voltage line 96 which extends through a set of normally-closed reset- ,20 waveform fed to the anodes of the diodes 64a, 64b, 64e,

unit 59a, 59b or 59e, ctc. involved which pulse is coupled Y to diode 74a, 74b or 74C, etc. through an associated condenser 70a, 70b or 70e, etc. connected to ground through resistors 72a, 72b, 72e, etc.,v the respective resistor condenser circuits forming dierentiating or peaking networks. The diodes 74a, 74b, or 74e filter out unwanted negative pulses generated by the diterentiating networks. Positive pulses pass through the above-mentioned diodes 74a, 74h, 74e, etc. to the control grid of suitable bistable trigger lcircuits 76a, 76b, 76o, etc. which may be oneshot multivibrator, pulse shaping which generate greatly amplified pulses in their output lines 78a, 78h, 78e, etc. respectively containing current transformers 80a, 80h, 80e, etc. The output of these current transting contacts 100 to the positive terminal 98 of a source of regulated direct current voltage. The negative terminal 99 of this voltage source is connected to the main or common ground line 92. winding 82a-3 isconnected to the branch ground line 90a. All of the windings of the relay units in each column corresponding to the third mentioned relay winding 82a-3, likewise extend between the associated branch ground lines 90a. 90b, 90e, etc. through the associated holding contacts corresponding to the holding contacts 82a-4 to the associated column high voltage branch lines 94a, 94b, 94e, etc.

In order fonany relay unit to be energized (Le. operate its contacts), -it is necessary that D.C. voltages of the proper polarity and magnitudes be simultaneously applied to the rst and second mentioned windings thereof corresponding to the windings 8241-1 and 8in-2. Ac cordingly, the comparator circuit output pulses appearing on the row input lines 10a, 10b, 10c, 10d, etc. and the high voltage conditions of the output lines of the coding formera are connected to an gates, 30-2a' if they' are associated with storage unit 10. If the comparator circuits being discussed are associated with the storage unit 10', then the outputs of these transformers would be connected to not gates like Sil-3b", previously mentioned.

The output of the gates are respectively connected to input lines 10a, 10b, etc. of the associated storage unit.

Figs. 6a and 6b show a less preferred form of storage unit 10" which may be subwtuted for the magnetic core storage units 10 or 10' insofar as a broad aspect of the invention is concerned. The storage unit shown in Figs.

6a and 6b is a relay matrix storage unit wherein relay units 82a-83a-84a, etc., 82b-83b-84b, etc., 82cmeans 8 feeding the column input lines`11a, 11b. llc, etc.,

are adjusted to values which will energize the relays if they are fed simultaneously to the input windings of any relay unit. In this way, the energized conditions of the relays represent the binary representations of the values of the variables associated with the various rows of relay units. As soon as any relay unit becomes energized, the

.associated holding contacts corresponding to contacts 8241-4 close to energize the third winding ofthe unit cor responding to winding 82a-3 from the source of direct current voltage connected to the terminals 98 and 99. The ux produced by the current iiowing in the windings 82a3 is suilcient to hold the relay in its energized condition in the absence of voltages on the other windings.

i, Energization of any particular relay closes the associated SSC-84e, etc., are respectively arranged in successive rows with the corresponding relay unit in each of the i l rows being arranged in respective columns. The relay f units in the various rows are fed by respective input lines 10a, 10b, 10c, 10d, etc. which may correspond to the similarly numbered input lines of the magnetic core matrix storage unit 10 or 10 previously described. Simi# larly, the relay units of the various columns are fed by respective column input lines 11a, 11b, 11e, etc. corresponding to the similarly numbered column lines of the magnetic core matrix storage unit 10 or -10' previously described. Since each of the relay units may be identically constructed, only one of these units, namely, relay unit82awi1lnowbedescribed. .'f

The relay units 82a has three windings 82a-l, 82a-2, and 820-3 (Fig. 6a) wound around a common core, holding contacts Bla-4 and binary code indicating contacts 824-5 (see Fig. 6b). The winding 82a-1 is connected between the associated row input line, which in the #5 contacts shown in Fig. 6b. which contacts are all identied similarly to the associated relay.

One of the terminals of each of the #5 contacts of the relay units of each column of relay units is connected to a common branch line 103a, 103b or 103e, etc. leading to a main high voltage line 104 extending to the abovementioned positive terminal 98. The other terminals of the contacts of the relay units in each row may be connected respectively to different contacts of a step switch 13-1a, 13-1b, 13-1c, or 131d, etc. which sequentially scan the various contacts in each row, and in row by row succession. If desired, instead of mechanical switches, electronic gating or switching means may be utilized. The wipers of the stepping switches 13-1a, 13-1b, 13-1c, 13-1d, etc. are connected respectively to successive stationary contacts of a master stepping switch 13 2 whose wiper extends to a suitable data handling device. Since the open and closed contacts represent opposite binary states, which are the presence and absence of a voltage, it can be seen that with the arrangement of the above deexample is indicated by reference numeral 10a, and a 75 scribed, the information readout from the contact matrix The other terminal of the n. j l shown in 6b will be binary code groups indicating the values of the associated variables.

Reference should now be made to Fig. 7 showing a still further modified and less preferred form of storage unit which falls within the purview of a broad aspect of the invention. In this embodiment, the storage unit and coding means utilize a roating magnetic drum 10"'. The drum hasa series of axially spaced storage sections 10"'-1, 10m-2, 10"-a, 10"'-b, 10m-c, 10m-d, etc. The rst section 10"'-1 may contain a magnetized pulseproducing point in each circumferential storage point or area of the drum, which magnetizedrpoint generates a pulse in a suitable pick-up head 1 f-3. The pulses generated in the pick-up head 10"'-1 take the place of the timing pulse source 16 in the various previously described embodiments and is used to synchronize the operation of the step wave generator 6. The second section 10"'-2 of the drum includes at each of said circumferential points or areas of the drum a series of axially spaced magnetized points providing a multi-bit binary coded indication identifying the 'number of the associated circumferential point on the drum relative to a starting or zero point thereon and thus represent the various possible values of the variables being monitored by the system. The second section 10"'-2 of the drum is thus a substitute for the coding means 8 previously described. A separate piekup head would, of course, be associated with each axial storage channel or point in drum section 10m-2. Each of the other axial storage sections of the drum, namely, sections l'"-a, 10m-b, 10"'-c, etc. has a recording and pick-up head associated therewith which is fed by respective input lines 10a, 10b, 10c, 10d, etc. connected to the outputs of the various comparator circuits above described. With the arrangement just described, it can be seen that during a cycle of operation of the output of the step wave generator 6, which is assumed to take place in one revolution of the drum, each of the storage sections 10"a, 10"-b, etc. of the drum will contain a recorded magnetic signal having a circumferential position corresponding to the multi-bit binary code group which identities the value of the associated variable. For read-out purposes, each of the pick-up and recording heads associated with the storage sections 10"'-a, 10m-b, 10'c, etc. are connected to successive stationary contacts of a suitable scanning switch, such as a telephone type stepping switch 13 2'. The rate of advancement of the wiper of the step switch 13 2' can be timed with the speed of rotation of the drum so that the output of the read-out heads associated with the different storage sections of the drum are successively connected to the wiper of switch 13-2' each revolution of the drum. As the circumferential position containing the recorded magnetic signal moves across the selected read-out head, a pulse is induced therein which appears on the wiper stepping switch 13-2'. This pulse is utilized to open a suitable normally-closed gate circuit 106 having inputs fed by the pick-up heads of the code storage section 10m-2. It can thus be seen that the output of the gate circuit 106 is a binary code V Y which represents the value of the variable associated with the storage section of the drum being scanned at any instant. t

lt should be understood that numerous modifications may be made of the various embodiments of the invention above described, without deviating kom the broader aspects of the invention. v

I claim as my invention: Y

l. An information handling system comprising a number of signal sources providing signal outputs whose amplitudes are functions of the values of respective varisables, a storage unit having separate storage positions :for data on each variable and separate inputs to said storage positions which are capable of receiving and storing dat: in said storage positions simultaneously, a source of a reference signal whose amplitude progressively I 16 the signal sources, a separate amplitude comparator cir- 'cuit for each of said signal sources, each comparator circuit including a rst and second input and an output, said first comparator circuit inputs being respectively connected to the outputs of said signal sources and `said second inputs thereof being connected in common to the output of said reference signal source, each of said comparator circuits including means for generating a given control signal at the output therf whenever the signals fed to said inputs thereof reach a given e of amplitude comparison, a coding meats common o all of said comparator circuits and operated in synchronimn with said reference signal source for providing multi-bit binary code groups progressively varying in synchronism with the change in level of the output of said reference signal source,`and means responsive to said comparator circuit output signals and the code indication of the coding means at the instant of generation of such signals for feeding signals to said respective storage unit inputs for storing in said storage positions indications of the binary code representing the value of the variables involved.

2. An information handling system comprising a number of signal sources providing signal outputs whose amplitudes are functions of the values of respective variables, a storage unit having separate storage positions for data on each variable and separate inputs to said storage positions which are capable of receiving and storing data in said storage positions simultaneously, a source ofl a reference signal whose amplitude progressively varies in a definite way, the incremental steps of the discretely varying reference signal being equivalent to a change in one apparent unit of value of the variables involved, a separate signal amplitude comparator circuit for each of said signal sources, cach comparator circuit including a first and a second input and an output, said first comparator circuit inputs being respectively connected to the outputs of said signal sources and said second inputs thereof being connected in common to the output of said reference signal source, each of said comparator circuits including means for generating a given control signal at the output thereof whenever the signals fed to said inputs thereof reach a given state of amplitude comparison, coding means common to all of said comparator circuits and operated in syncbronism with said `reference signal source for providing code groups representing a number progressively varying by one unit at each step in synchronism with the change in level of the output of said reference signal source, and means responsive to said comparator circuit output signals and the code indication of the coding means at the instant of generation of such signals for feeding signals to said respective storage unit inputs for storing in said storage positions indications of the code representing the value of the variables involved.

3. An information handling system comprising a number of signal sources providing signal outputs whose amplitudes are functions of the values of respective variables, a source of a reference signal whose amplitude progressively varies inl discrete steps independently of the Aoutput of the signal sources, a separate signal amplitude comparator circuit for each of said signal sources,

each comparator circuit including a first and a second input and an output, said tirst comparator circuit inputs being respectively connected to the outputs of said signal sources and said second inputs thereof being connected in common to the output of said reference signal source, each of said comparator circuits including means for generating a given control signal at the output thereof whenever the signals fed to said inputs thereof reachV a given state of amplitude comparison, coding means common to all of said comparator circuits and comprising a pulse counter having respective binary code bit output lines and adapted to provide on said lines a multi- Vif in a dnil -Wy indpdm1` gf Figui 9 f ,7,5 bi1 binary coded signal representing the number of pulses fed from a given reference time, a source of control pulses feeding said pulse counter, means' for pro-y gressively changing the level of the output of said reference signal source in synchrcnism with the feeding of to said pulse counter, a storage unit having a separate data storage position for each signal source, each storage position having a number of binary code bit storl signal source, means connecting each code bit output line age points each including a rst and a second input, Y

of said coding means to all of the second inputs at the Y corresponding bit storage4 point of each storage posi. tion, and means for providing at each bit storage point a rst binary indication when the binary signal fed thereto from said coding means to the second input thereof is a given predetermined one of two possible binary signais and the tirst input thereof simultaneously receives said control signal from the associated comparator cir-I cuit, and to provide at each bit storage point a second binary'indication whenthe input thereof from said cod-v ing means is the other binary signal and the tirst input l receives said control signal, the storage positions thereby receiving binary c oded data representing the values of associated variables. .v y

4. An infomation handling system comprising a number of signal sources providing signal outputs whose amplitudes are functions of the values of respective variables, a source of a reference signal whose amplitude progressively varies in a definite way, a separate signal amplitude comparator circuit for each of said signal sources, each comparator circuit including a rst and a second input and an output, said tirst comparator circuit inputs being respectively connected to the outputs of said signal sources and said second inputs thereof being connected in common to the output of said reference signal source, each of said comparator circuits including means for generating a given control signal at the output thereof `whenever the signals f ed to said inputs therevof reach a given state of arr'iplitude comparison, coding means common to all of said comparator circuits and pair of input windings and an output winding, one of said input windings of each' core meam being connected to thel output of a different one of said signal sources and the second input windings of said core means being connected in common to the output of said reference signal source so that the magnetomotive forces produced by the current in the input windings thereof oppose one another, the effect in'each core means of the incremental steps of the discretely varying reference signal being equivalent in magnitude to a change in one apparent unit of value of the variables involved, the nature of each-of said core means and the windings thereof being such that with the magnetomotive forces produced by the current in said input winding being alike in magnitude the next change in level of said reference signal will produce a sutlicient change in magnetomotive force to cause the point cf operation on the hysteresis curve thereof to shift between the knees of the hysteresis curve to change the state of magnetization of the core means operated in synchronism with said reference signal source V for providing on respective binary code bit output lines multi-bit binary code groups progressively varying in synchronism with the change in level of the output of said reference signal' source, a storage unit having a separate data storage position for each signal source, each storage position having a number of binary code bit storage points each including a rst and a second input, means coupling the output of each comparator circuit to all of the tirst inputs of the bit storage points of the storage position to contain data on the associated signal source, means connecting each code bit output line of said coding -meanstoallofthesecondinputsatthecorrcsponding bit storage point of each storage position, and means for providing at each bit ystorage pointa first binary indication when the binary signal fed thereto Afrom said coding means to the second input thereof is a given pre determined one of two possible binary signals and theV 'first input thereof simultaneously receives said control signal from the associated comparator circuit, and to provide at each bit storage point a second binary` indi l plitudes are functions of the values of respective vari--V ables, a source of reference signal whose amplitudeprogressively varies in discrete steps, a separate amphtude comparator circuit for each of said signal sources, each comparator circuit including satm'able magnetic core meansoftherectangularhysteresiscm'vetypehavmga and produce a control pulse in the output winding thereof, coding means common to all of said comparator circuits and operatedin synchronism with said reference signal source for providing on respective binary code bit output lines binary coded signals representing a number progressively varying by one unit at each step in synchronism with the change in level of the output of said reference signal source, and means responsive to said comparator circuit control pulses and the code indication of the coding means at the instant of generation of said pulses for storing in said storage positions indications of the binary code representing the value of the variables involved. y

6. An information handling system comprising a number of signal sources providing signal outputs whose amplitudes are functions of the values of respective variables, a4 storage unit having separate storage positions for data on each variable and separate inputs to said storage positions which are capable of receiving and storing data in said storage positions simultaneously, a source of a reference signal whose amplitude progressively varies in discrete steps, a separate amplitude comparator circuit for each of said signal sources, each comparator circuit including saturable magnetic core means of the rectangular hysteresis curve type having a pair of input windings and an output winding, one of said input windings of each core means being connected to the output of a different one of 4said signal sources and the second input windings of each core means being connected in common to the output of said reference voltage source so that the magnetomotive forces produced by the current in the input windings thereof oppose one another, the nature of each of said core means and the windings thereof being such that a change of one step in the level of said reference signal once the knee of the hysteresis curve thereof is reached will produce a suicient change in magnetomotive force to cause the point of operation on the hysteresis curve to shift between the knees thereof to change the state of magnetization of the core means and produce a control signal pulse in the output winding thereof. coding means common to all ot said comparator circuits and operatedin syncrronism with said reference signal source for pro- -viding code signals representing a number progressively varying by one unit at each step in synchronism with the change in level of the output of said reference signal source, and means resporsive to said comparator circuit output pulses and the de indication of the coding means at the instant of generation of said pulses for feeding signals to said respective storage unit inputs ables, a source of a reference signal whose amplitude progressively varies in discrete steps, a separate amplitude comparator circuit foreach of said signal sources, each comparator circuit including saturable magnetic core means of the rectangular hysteresis curve type having a pair of input windings and an output winding, one of said input windings of each core means being connected to the output of a different one of said signal sources and the second input windings of said core means being connected in common to the output of said reference signal source so that the magnetomotive forces produced by the current in the input windings thereof oppose one another, the elect in each core means of the incremental steps of the discretely varying reference voltage being equivalent in magnitude to a change in one apparent unit of value of the variables involved, the nature of each of said core means and the windings thereof being such that a change of one step in the level of said reference signal once the knee of the hysteresis curve thereof has been reached will produce a suicient change in magnetomotive force to cause the point of operation on the hysteresis curve to shift between the knees thereof to change the state of magnetization of the core and produce a control signal pulse in the output winding thereof, coding means common to all of said A. comparator circuits and operated in synchronism with said reference signal source for providing on respective binary code bit lines multi-bit binary coded signals pro'- gressively varying in synchronisrn with the change in level of the output of said reference signal source, a storage unit having a separate storage position for each signal source, each storage position having a number of binary code bit storage points each including a rst and a second input, means connecting the pulse output of each comparator circuit to the trst inputs of the bit storage points of the storage position for data on the associated signal source, means connecting each code bit output line of said coding means to the second inputs at the corresponding bit storage point of each storage position, and means for providing at each storage point a first binary indication when .the binary signal fed thereto from said coding means to one of the inputs thereof is a given one of two possible binary signals and the other input thereof simultaneously receives said control signal pulse from the associated comparator circuit, and

. to provide at each bit storage point a second binary indication when the input thereof from said coding means is the other binary signal and the rst input receives said control signal.

8. An information handling system comprising a number of signal sources providing signal outputs whose amplitudes are functions of the valu of respective variables, a source of a reference signal whose amplitude progressively varies in discrete steps, a separate voltage comparator circuit for each of said signal sources, each comparator circuit including saturable magnetic core means of the rectangular hysteresis curve type having a pair o f input windings and an o'utput winding, one of said input windings of each core means being connected to the output of a different one of said signal sources and the second input windings of saidcore means being connected in common to the output of said reference signal source so that the magnetomotive forces produced by the current in the input windings oppose one another, the elect in each core means of the incremental steps of the discretely varying reference voltage being equivalent in magnitude to' a change in one apparent unit of value of the variables involved, the nature of each of said core means and the windings thereof being such that a change of one step in the level of said reference signal once the knee of the curve has been.

reached will produce a sufficient change in magnetomotive l force to cause the point of operation on the hysteresis 20 means and produce a control pulse in the output winding thereof, coding means common to all of said comparator circuits and comprising a pulse counter adapted to provide on a number of binary code bit output lines thereof a multi-bit binary coded signal representing the number of pulses fed thereto from a reference time, a source of control pulses feeding said pulse counter, means for progressively changing the level of the output of said reference signal source in synchronism with the feeding of pulses to said pulse counter, a storage unit having a separate storage position -fdr each signal source, each storage position having a number of binary code bit storage points each comprising a magnetic core storage element including a trst and a second input winding and an output winding, means connecting the pulse output of each comparator circuit to the tst input windings of the bit storage points of the storage position for data on the associated signal source, means connecting each code bit output line of said coding means to the secoind input core windings at the corresponding bit storage point of each storage position, said core elements each being driven from a reference state of magnetization to the opposite state of magnetization when the binary signal fed thereto from said coding means to one of the inputs winding thereof is a given one of two possible binary signals and the other input winding thereof simultaneously receives said control signal pulse from the associated comparator, the storage positions thereby receiving binary co'ded data representing the values of associated variables, and read-out means for feeding read-out pulses to the core windings of each storage position in succession which pulses drive the cores set from said opposite state of magnetization to said reference state of magnetization and generate pulses in the output windings thereof, whereby binary coded and an output, said rst comparator circuit inputs being respectively connected to the outputs of said signal sources, said second inputs being connected in common to the output of said referce signal source, each of said comparator circuits including means for generating a given co'ntrol signal at the output thereof whenever the signals fed to said inputs thereof reach a given state of comparison, coding means common to all of said comparator circuits and synchronized with said reference signal source for providing on respective binary code bit lines multi-bit binary coded signals progressively varying in synchronism with the change in level of the output of said reference signal source, a storage unit having a separate storage position for each signal source, each storage position having a number of binary code bit storage points each comprising a magnetic-core storage element including a first and a'second input winding and an output winding, means connecting the pulseoutputofeachcomparatordrcuittotherst input windings of the bit storage points orf the storage position for data on the associated signal source, means connecting each code bit output line of said coding means to the second input core windings at the corresponding bit storage point of each storage position, said core elements each being driven from a reference state of magnetization to the opposite state of magnetization when the binary signal fed thereto from said coding meanstooneoftheinputwindingsthereofisagiv oneoftwopossiblebinarysignalsandtheotberinput winding thereof simultaneously receives said control ber of signal sources providing signal outputs whose amplitudes are functions of the values of respective variables,

a source of a reference signal which progressively varies in discrete steps, the incremental steps of the discretely varying reference signal being equivalent to a change in one apparent unit of value of the variables involved, a separate amplitude comparator circuit for each of said signal sources, each comparator circuit including a first and a second input and an output, said first comparator circuit inputs being respectively connected to the outputs of said signal sources, said second inputs being connected in common to the output of said reference signal source, each of said comparator circuits including means for generating a given control signal at the output thereof whenever the signals fed to said inputs thereof reach a given state of comparison, coding means common lto all of said comparator circuits and syn- A chronized with said reference signal source for providing on respective binary code hit output lines multi-bit binary' coded signals progressively varying in synchronism with the change in level of the output of said reference signal source, a storage unit having a separate storage position for each signal source, each storage position having a number of binary code bit'storage points each comprising a magnetic core storage element including a first and a second input winding and an output winding, means connecting the pulse output of each comparator'circuit to the first input windings of the bit storage points of the storage position for data on the associated signal source, means connecting each code bit output line of said coding means to the second input core windings at the corresponding bit storage point of each storage position, said core elements each being driven from a reference state of magnetization to the opposite state of magnetization 'when the binary signal fed thereto 'orn said coding means to one of the input windings thereof is a given one of two possible binary signals and the other input winding thereof simultaneously receives said control signal pulse from the associated comparator circuit, and read-out means for feeding readlout pulses to the core windings of each storage position in succession which pulses drive the cores set from said opposite state of magnetization to said reference state of magnetization and generate pulses in the output windings thereof, subsequent to the completion of a scanning cycle where the.reference signal source has scanned the range of anticipated values of said signal source outputs, whereby binary coded pulse groups are generated in the output windings of the variables involved` ll. An information handling system comprising a number of signal sources providing signal outputs whose amplitudes are functions of the values of respective variables, a source of a reference signal which progres- A sively varies in discrete steps, a separate amplitude comparator circuit for each of said signal sources, each comparator circuit including a first and a second input and an output, said first comparator circuit inputsl being respectively connected to the outputs of said signal sources, said second inputs being connected in common to the output of said reference signal source, each of said comparator circuits including means for generating a given control signal at the output thereof whenever the signals fed to said inputs thereof reach a given state of comparison, coding means common to all of said comparator circuits and comprising s pulse counter adapted sassari to provide ona' number of binary code bit output lines thereof a multi-bit binary coded signal representing the numberofpulsfedtheretofromareferencetime,a

l source of control pulses feeding said pulse counter, means responsive to said pulse source for progressively changing the level of the output of said reference signal source in synchronism with the feeding of pulses to said pulse counter, a storage unit having a separate storage position for each signal source, each storage po'sition having a number of binary code bit storage points each comprising a magnetic core storage elanent including a rst nndasecond input winding andanoutput windingmeans connecting the pulse outputof each comparator circuit to the first input windings of the bit storage points of the storage position for data on the associated signal source, means connecting each code bit output line of said coding means to the second input windings at the corresponding bit storage point of each storage position, said core clements each being driven from a reference state of magnetization to the opposite state of magnetization .when the binary signal fed thereto from said coding means to one of the input windings thereof is a given one of two po'ssible binary signals and the other input winding thereof simultaneously receives said control signal pulse from the associated comparator circuit, and read-out means for feeding read-out pulses to thecore windings of each storage position which pulses drive the cores set from said opposite state of magnetization to said reference state of magnetization and generate pulses in the output windings thereof, whereby binary coded pulse groups are generated in the output windings of the cores of each storage position representing the values of the variables involved.

12. An information handling system comprising a 'number of signal sources providing signal outputs whose amplitudes are functions of the values of respective variables, a source of a reference signal which cyclically progressively varies in a denite way, a separate amplitude comparator circuit for each of said signal sources, each comparator circuit including a rst and a second input and an output, said first comparatorcircuit inputs being connected to the outputs of said signal sources and the second inputs thereof being connected in common to the output of said reference signal source, each of said comparator circuits including means for generating a given control signal at the output thereof whenever lthe signals fed to said inputs thereof reach a given state of comparison, coding means common to all of said comparator circuits and synchronized with saidv reference voltage source for providing on respective binary co'de bit output lines multi-bit binary coded signals progressively varying in synchronism with the change in level of the output of said reference signal source, a pair of storage units each having separate storage positions for data on respective variables, each storage position having a number of binary code bit storage points each comprising a first and a second input, means operatively coupling at least some of said comparator circuits respectively to the rst inputs of the storage positions'of one of the storage units during alternate cycles of said reference signal and operatively coupling at least some of said comparator circuits respectively to the first inputs of the storage positions of the 'other storage unit during the intervening alternate cycles of said reference signal, means operatively coupling each binary code bit output line of said coding means to the corresponding bit storage point of said storage units in synchromsm with and in the same order as the outputs of said comparator circuits are operatively connected to said inputs of said storage positions of said respective storage units.

means associated with each of said storage units for of simultaneously receives said control signal fro'm the associa-ted comparator circuit, and to provide at each bit storage point a second binary indication when the input thereof from said coding means is the other binary signal and the first input receives said control signal, the storage po'sitions of Asaid storage units thereby receiving binary coded data representing the values of the variables, and switching means for alternating coupling read-out pulses between the inputs of the storage positions of said storage units in the opposite order in which the coding means and comparator circuit outputs are operatively connected to said storage units, whereby storage of data is taking'place in one storage unit while the circuits respectively to the ist input windings of the data stored in the other storage unit during the previous scanning cycle is being read out to said common output device.

13. An information handling system comprising, a

4number of signal sources providing signal outputs whose vamplitudes are functio'ns of the values of respective varicomparator circuits including means for generating a given control signal at the output thereof whenever the signals fed to said inputs thereof reach a given state of comparison, coding means commo'n to all of said comparator vcircuits and synchronized with said reference voltage source for providing on respective binary code bit output lines. multi-'bit binary coded signals progressively varying in synchronism with the change in level of the output of said reference signal source, a pair of storage units each having separate storage positions for dataon respective variables, each storage position having a number of binary code bit storage points each comprising a magnetic core storage element including a rst and a second input winding, means operatively coupling at least some of said comparator circuits respectively to the first input windings of the storage po'sitions of one of the storage units during alternate cycles of said reference signal and operatively coupling at least some of said comparator storage positions of the other storage unit during the intervening alternate cycles of said reference signal, means operatively coupling each binary code bit output line of said coding means to the corresponding bit storage point of said storage units in synchronism with and in the same order as the outputs of said comparator circuits are operatively connected to said input windings of said storage positions of said respective storage units, said core storage elements each being driven from a reference state of magnetization to a second state of magnetization when the binary signal fed thereto from said coding means to one of the input windings thereof is a given one of two possible binary signals and the other input winding thereof simultaneously receives said control signal from the associated comparator circuit, the storage positions of said storage units thereby receiving binary coded data representing the values of the vari ables, and means for alternating coupling read-out pulses between the input windings of the storage positions of said storage units in the opposite order in which the coding means and comparator circuit outputs are switched between said storage units, the read-out pulses driving the cores in said second state of magnetization back to said reference state of magnetization thereby to produce pulses in the output windings thereof, and switching means for alternately coupling the pulse signals generated in said output windings of said respective storage units to a common output device, whereby storage o'f data is taking place in one storage unit while the data stored in the other storage unit during the previous scanning cycle is being read -out to said common output device.

Refmns cited in me me of this patent UNITED STATES PATENTS A Higham sept. 21, 1949 

